In the macroscopic realm, there is often an undesirable restriction of the relative movement between two surfaces. This tendency of two surfaces to stick to each other is called friction and can be significantly reduced by introducing an intermediate material, i.e. a lubricant, that is slippery between the surfaces.
In the microscopic realm, there also is an undesirable restriction of the relative movement between two surfaces. Unfortunately, unlike the macroscopic realm, the introduction of an intermediate material between the surfaces may actually increase the propensity of micro components to stick together. Furthermore, in the micro and nano realms short-range forces, such as the van der Waals and electrostatic forces, become extremely important and often lead to serious limitations in the overall design and miniaturization of components. This effect is often referred to as stiction.